Method and an apparatus for removing the skin from a sausage

ABSTRACT

A method of removing the skin ( 7 ) from a sausage ( 1 ) comprises a plurality of steps. First, an end portion ( 2 ) of the sausage ( 1 ) is cut off, whereafter the skin ( 7 ) is grasped by gripping means ( 3 ) in diametrically opposed positions. Thereafter, an incision is made in the sausage ( 1 ) in its longitudinal direction by a knife ( 6 ), and the gripping means ( 3 ) and the sausage ( 1 ) are displaced in relation to one another in the longitudinal direction of the sausage ( 1 ) so that the skin ( 7 ) is pulled off in this direction. An abutment member ( 5 ) counteracts the tendency of the sausage ( 1 ) to move with the gripping means ( 3 ) when these are displaced. An apparatus for removing the skin ( 7 ) from a sausage includes a substrate for supporting the sausage, gripping means ( 3 ), a knife ( 6 ) and a displacement device ( 8 ). The gripping means ( 3 ) are disposed on either side of the sausage ( 1 ) and the knife ( 6 ) is disposed at the surface of the sausage ( 1 ) between them.

TECHNICAL FIELD

The present invention relates to a method for removing the skin from asausage and comprises the steps that an end portion of the sausage iscut off, that the skin is grasped by gripping means, that an incision ismade in the sausage by a knife, that the gripping means and the sausageundergo a relative displacement in the longitudinal direction of thesausage and that the skin is pulled off in the longitudinal direction.

The present invention also relates to an apparatus for removing the skinfrom a sausage.

BACKGROUND ART

Patent specification SE 433 032 discloses a machine for removing skinfrom sausages which are interconnected to one another in a string.First, the sausages pass through a steam pipe to loosen the skin.Thereafter, the sausages are led up to a pair of feeder rollers in ordersubsequently to be cut from above by a knife blade edge. The skin ispulled off in that the sausages pass over a perforated suction roller ora vacuum wheel.

One of the drawbacks inherent in this apparatus is that the skin of thesausage, and thereby the subjacent surface, is heated to a relativelyelevated temperature, which is not always desirable, among other thingsfor reasons of shelf life. Another drawback is that a perforated suctionroller is operationally unreliable since the perforations may readilybecome blocked by skin slivers or parts from the sausages. Furthermore,it would probably be difficult to clean the suction roller without themachine having to be partly dismantled. Finally, the method is likely tobe difficult to employ for sausages which are not connected into astring.

EP 0 721 738 discloses an apparatus and a method for removing the skinfrom sausages and the like. Initially, the skin is severed in the endportion. A gripping device is moved in inside the edge of the skin andclamps this fast against a frame. Thereafter, the skinning unit, onwhich the gripping device and the frame are disposed, is moved towardsthe opposite end of the sausage, the skin being pulled off axially. Therisk that the skin becomes folded or otherwise crumpled together isquite large, in particular when long sausages are involved. As a result,there is a quite serious risk of operational stoppage.

EP 0 732 054 discloses a method which is based on the principle that asausage is provided with two curved incisions along each respective sideof the sausage. Thereafter, the upper half of the sausage skin is pulledoff, followed by the lower half. The two halves are connected togetherin the one end of the sausage, but the risk would appear to be quitelarge that the skin breaks or ruptures in the connection between theupper and the lower half, with consequential operational stoppage.

EP 0 509 477 shows how the skin may be removed from a sausage in that aknife cuts a longitudinal incision on the upper side of the sausage. Theskin is grasped on each respective side of the incision with the aid oftwo suctions strips or beads. The suction strips are disposed on twoarms which are pivoted outwards and thereby entrain the skin with them.The drawbacks inherent in a construction according to this PatentSpecification are that the use of suction devices so close to theincision entails risks that only a part of the skin will be pulled off,and/or that the suction devices fasten in the sausage inside theincision.

PROBLEM STRUCTURE

The present invention has for its object to formulate the methodintimated by way of introduction such that it may, with greatoperational reliability and rapidity, be employed for removing the skinfrom a sausage regardless of the appearance of the end portion of thesausage and regardless of whether there may be metal parts or the likedisposed at the end portion of the sausage. Furthermore, the outside ofthe skin and any matter which has been in contact with it may not comeinto contact with the skinned sausage.

The present invention further has for its object to realize an apparatusfor removing the skin from a sausage. Thus, the present inventionrelates to an apparatus which is easy to operate, which is extremelyreliable in operation, which is flexible and which may therefore readilybe adapted to different types and sizes of sausages, regardless of theappearance of the skin at the end of the sausage. Furthermore, theoutside of the skin and any matter which has been in contact with it maynot come into contact with the skinned sausage.

SOLUTION

The objects forming the basis of the present invention will be attainedin respect of the method if this is characterized in that the grippingmeans grasp the skin in diametrically opposed positions, and that theknife cuts the skin in the longitudinal direction of the sausage.

The objects forming the basis of the present invention will be attainedin respect of the apparatus if this is characterized in that thegripping means are disposed on either side of the sausage, and that theknife is disposed below the sausage.

Further advantages will be attained according to the present inventionif the method is given one or more of the characterizing features as setforth in appended subclaims 2 to 4 and if the apparatus is given one ormore of the characterizing features as set forth in appended subclaims 6to 9.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detailhereinbelow, with particular reference to the accompanying Drawings. Inthe accompanying Drawings:

FIG. 1 is a perspective view of the present invention before thegripping means have grasped the sausage skin;

FIG. 2 is a perspective view of the apparatus according to the presentinvention at a later stage in the work cycle;

FIG. 3 is a straight front elevation of the apparatus according to thepresent invention, it being shown how the knife cuts the sausage skin;

FIG. 4 is a perspective view corresponding to that of FIGS. 1 and 2 in alater stage of the work cycle;

FIG. 5 is a perspective view a further distance along the work cycle;and

FIG. 6 is a perspective view corresponding to that of FIG. 5 during afinal phase of the work cycle.

DESCRIPTION OF PREFERRED EMBODIMENT

The present invention relates to a machine according to FIG. 5. Themachine has a legged frame 11 with preferably four legs. Further, thereis provided a support arrangement 10 on which the sausage 1 is intendedto rest. The support arrangement 10 is adjustable for different sausagesizes and, in the present embodiment, consists of quite slim cylinders12 in relation to the thickness of the sausage 1. The cylinders 12 aredisposed on a system of rocker arms 22 which are pivotally disposed inthe machine in the pivot 23 and a corresponding pivot at the other endof the machine. The distance between the cylinders 12 may be adapted tothe thickness of the sausage 1. The position of the cylinders 12 alsodetermines the position sausage 1 in the vertical direction.

A knife 6 on a knife holder 21 is disposed between the cylinders 12.

Ahead of the machine, there is disposed a feeder device which is notshown in the Figure. The sausage 1 is intended to be fed to the machinetransversely of its own and the cylinders' 12 longitudinal direction, sothat it will rest above the cylinders 12 with substantially the samelongitudinal direction. During one work cycle, the sausage 1 is fed tothe right in the Figure along the cylinders 12 until the entire sausage1 is located on a discharge table 13 which is shown by broken lines inthe Figure.

Above the sausage 1 and the support arrangement 10, there are two linearguides 14, 15 which are longitudinal. A displacement device 8 and a unit16 provided with gripping means and abutment means, respectively, aremovably disposed on the guides 14 and 15. In addition, each one of thelinear guides 14 and 15 is provided with a drive means for displacingthe units disposed on the guides. The displacement device 8 and the unit16 provided with gripping means 3 are movable independently of eachother and may pass one another without hindrance. For example, the drivemeans may consist of chains, belts, compressed air or the like, but thedrive means are not shown in the Figures.

FIG. 1 shows in perspective the apparatus for removing the skin from asausage in the beginning of a work cycle. The sausage 1 has, with theaid of the displacement device 8 (shown in FIG. 5), been advanced alonga support arrangement 10 which, in the Figure, is shown as cylinders,but which could just as well be other types of rails of low frictionsince the sausage is not intended to rotate during the work cycle. Onboth sides of the end portion 2 of the sausage, the gripping means arein their respective starting positions. Each one of the gripping means 3consists of two mutually reciprocal plates 4.

The plates 4 are substantially horizontal and approximately parallelwith each other. The gripping means 3 on each respective side of thesausage lie substantially in the same plane. In the initial phase, theyassume a position flush with the center of the sausage. The edges of theplates 4 are quite blunt in order not to cut open the skin 7, and forthe greater part abut against the sausage 1 when this is advancedtowards the gripping means 3. In principle, the edges are approximatelytangential to the rounded end portion 2 of the sausage 1. Seen fromabove, the edges of the plates 4 make an angle with the longitudinaldirection of the sausage 1. In the preferred embodiment, this angle isof the order of magnitude of about 30-60°.

In the Figure, the sausage 1 has been advanced so far by thedisplacement device 8 that it firmly abuts against, or is urged againstthe gripping means 3.

In FIG. 2, the plates 4 in the gripping means 3 have been moved towardsone another and the skin 7 has been clamped between the plates 4 in thegripping means 3.

At the same time (as shown in FIG. 3), the knife 6 has begun to cut upthe skin 7 on the underside of the sausage 1. The knife 6 is disposedbetween the cylinders 12 included in the support arrangement 10. Theknife 6 is pivotally disposed in order for it to be able to cut anincision both in the end portion 2, which is cupped, and along theunderside of the sausage 1. For the pressure of the knife edge againstthe sausage 1 to be sufficient to cause the skin 7 to rupture but not todamage the rest of the sausage 1 to any appreciable degree, the knife 6is biased upwards, either by a weight or by spring force.

In FIG. 4, the gripping means 3 have been raised up a distance to aposition above the sausage 1i under the action of a piston and cylinderassembly 17 which, by means of guide rods 18 in slide blocks 19, actuatea carrier 20 on which the gripping means 3 are disposed. Since thepiston and cylinder assembly 17 is obliquely inclined, the skin 7 will,already when the gripping means 3 are raised, be pulled loose from thesausage 1. The direction of movement is at approximately 40-70° to thevertical, so that the gripping means 3 move in over the sausage 1 awayfrom its end portion 2. When the gripping means 3 have reached theirupper position, the sausage 1 may freely pass under them. It is clearlyvisible in the Figure how a portion of the sausage 1 has been freed ofits skin 7.

Since the loosened portion of the skin 7 extends between the sausage 1and the gripping means 3, which are located above the sausage 1, thesausage 1 has a tendency to move upwards. In order to counteract thismovement, an abutment member 5 is disposed above the sausage 1approximately flush with the gripping means 3 on the unit 16 providedwith the gripping means 3. In the preferred embodiment, the abutmentmember 5 substantially has the form of a V and is disposed in a planewhich is approximately parallel to the plane of the gripping means 3.

FIG. 5 shows how the unit 16 with the gripping means 3 and abutmentmember 5 has moved a distance along the sausage along the upper linearguide 14. At the same time, the displacement device 8 has moved in theopposite direction along the lower linear guide 15 and shunted thesausage 1 ahead of it in its longitudinal direction.

In FIG. 6, the unit with gripping means and abutment member has passedthe sausage 1 and the displacement device 8. In order to retain thesausage 1 in its position when the last portion of the skin 7 is pulledloose, a retainer device 9 is provided for holding the sausage in itsfront portion. The retainer device 9 exercises a light pressure on thesausage 1 and holds it in place against the discharge table 13.

Throughout the entire process when the skin 7 is pulled off, it shouldbe noted that the outside of the skin 7 does not come into contact withthe skinned sausage 1. Nor does any matter which has been in contactwith the outside of the skin come into contact with the sausage 1. As aresult, the shelf life of the product is increased substantially.

When the entire skin casing 7 has been pulled off from the sausage 1,the gripping means 3 will release the grip on the skin 7 and this isallowed to fall off, preferably between the cylinders 12 or railsincluded in the support arrangement 10. Thereafter, the unit with thegripping means 3 and the abutment member 5 and the displacement device8, respectively, reassumes its original starting position and a newsausage 1 may be processed.

DESCRIPTION OF ALTERNATIVE EMBODIMENTS

For the preferred embodiment in the foregoing, directions were given,for example ‘upwards’, ‘downwards’, ‘to the side’, and positions suchas, for example, ‘above’, ‘below’, in order to describe the method andthe apparatus for removing the skin from a sausage. In the description,reference has been made to the accompanying Drawings, and theorientation of the parts included in the apparatus as shown in theDrawings.

It is naturally possible to move the included components in relation tothat described above without, to this end, deviating from the inventiveconcept as herein disclosed.

Principally, this may be put into effect in that the components includedin the apparatus are rotated through up to 180° around the longitudinalaxis of the sausage. In this embodiment, the knife 6 should bespring-biased if biasing by means of a weight were to prove insufficientor impossible because of the orientation of the knife 6.

In particular, the knife 6, the gripping means 3 and the abutment member5 may be rotated about 90° around the longitudinal axis of the sausage.In this case, accessibility may be improved and the infeed of thesausage may possibly be facilitated.

Further, it has been described how the knife 6 cuts the skin 7 along theentire length of the sausage 1. One alternative could be a shorterincision which functions as a tear indication on the further removal ofthe skin 7. By way of suggestion, the incision may be placed in thelongitudinal direction of the sausage 1 but only in the rounded endportion 2 of the sausage 1, so as to terminate in the region where thesausage is of uniform thickness.

The present invention may be modified without departing from the scopeof the appended Claims.

What is claimed is:
 1. A method for removing the skin (7) from a sausage(1), comprising the step that an end portion (2) of the sausage is cutoff, that the skin (7) is grasped by gripping means (3), that anincision is made in the sausage by a knife (6), that the gripping means(3) and the sausage (1) undergo a relative displacement in thelongitudinal direction of the sausage (1), and that the skin (7) ispulled off in the longitudinal direction, characterized in that thegripping means (3) grasps the skin (7) in diametrically opposedpositions, the knife (6) cuts the skin (7) in the longitudinal directionof the sausage (1), said gripping means (3) are moved a distancetransversely of the longitudinal direction of the sausage once thegripping means have grasped the skin (7), and an abutment member (5)prevents the sausage (1) from moving with the gripping means when saidgripping means are displaced, for which reason the skin (7) is pulledoff.
 2. The method as claimed in claim 1, characterized in that thesausage (1) is urged by a retainer device (9) against an abutment whenthe last portion of the skin (7) is pulled of.
 3. An apparatus forremoving the skin (7) from a sausage (1) comprising a substrate forsupport, gripping means (3), a knife (6) and a displacement device (8),characterized in that said gripping means (3) are disposed for contacton opposing sides of the sausage (1), and that the knife (6) is disposedat a surface of the sausage (1) between said gripping means, whereinsaid displacement device is designed to have the gripping means andsausage undergo a relative displacement in a longitudinal extensiondirection of the sausage.
 4. The apparatus as claimed in claim 3,characterized in that said gripping means (3) are disposed to move, insubstantially parallel fashion, a distance away from the sausage (1) andthe knife (6) after engagement with the sausage skin (7).
 5. Theapparatus as claimed in claim 3, characterized in that an abutmentmember (5) is disposed behind said gripping means (3) relative to adirection of movement of the sausage (1) for preventing movement of thesausage in a direction away from the knife.
 6. The apparatus as claimedin claim 3, characterized in that the knife (6) is movably disposedtowards and away from the sausage.
 7. The apparatus as claimed in claim3, characterized in that a retainer device (9) is provided for retainingthe sausage (1) in its position when the last portion of the skin (7) ispulled off.
 8. The apparatus as claimed in claim 4, characterized inthat an abutment member (5) is disposed behind said gripping means (3)relative to a direction of movement of the sausage (1) for preventing amovement of the sausage in a direction away from the knife.
 9. Theapparatus as claimed in claim 4, characterized in that the knife (6) ismovably disposed towards and away from the sausage.
 10. The apparatus asclaimed in claim 5, characterized in that the knife (6) is movablydisposed towards and away from the sausage.
 11. The apparatus as claimedin claim 4, characterized in that a retainer device (9) is provided forretaining the sausage (1) in its position when the last portion of theskin (7) is pulled off.
 12. The apparatus as claimed in claim 5,characterized in that a retainer device (9) is provided for retainingthe sausage (1) in its position when the last portion of the skin (7) ispulled off.
 13. The apparatus as claimed in claim 6, characterized inthat a retainer device (9) is provided for retaining the sausage (1) inits position when the last portion of the skin (7) is pulled off. 14.The apparatus of claim 3, wherein said substrate includes guide surfacesfor guiding longitudinal movement of both said gripping means anddisplacement device in opposite longitudinal directions.
 15. Theapparatus of claim 3 wherein said displacement device is a singlecontact device positioned for sausage end contact.
 16. A method forremoving the skin (7) from a sausage (1), comprising the steps ofcutting an end portion (2) of the sausage, grasping the skin (7) withgripping means (3), forming an incision in the sausage by a knife (6),subjecting the gripping means (3) and the sausage (1) to a relativedisplacement in the longitudinal direction of the sausage (1), andpulling of skin (7) off in the longitudinal direction, and, in the stepof grasping the skin, the gripping means (3) grasps the skin (7) indiametrically opposed positions, and in the step of cutting the knife(6), the knife cuts the skin (7) in the longitudinal direction of thesausage (1), wherein said gripping means (3) are moved a distancetransversely of the longitudinal direction of the sausage once thegripping means have grasped the skin (7), and an abutment member (5)prevents the sausage (1) from moving with the gripping means when thegripping means are displaced, for which reason the skin (7) is pulledoff.
 17. An apparatus for removing skin from a sausage, comprising: asupport substrate extending in a longitudinal direction and dimensionedto receive and support a sausage; a first gripper positioned to a firstside of the sausage when supported on said support substrate, said firstgripper having a first side skin gripper assembly which shifts saidfirst gripper between a skin gripping mode and a skin release mode; asecond gripper positioned to a second side of the sausage, which secondside opposes said first side of the sausage, when supported on saidsupport substrate, said second gripper having a second side skin gripperassembly which shifts said second gripper between a skin gripping modeand a skin release mode; a sausage displacement device; a knife arrangedfor sausage skin contact when the sausage is supported on said supportsubstrate, said knife being positioned at a location between the firstand second sides of the sausage; and a gripper adjustment device whichpositionally adjusts said first and second grippers toward and away fromthe sausage and in a direction transverse to the longitudinal direction;said support substrate further comprising longitudinal guide supportsurfaces for guiding longitudinal movement of said sausage displacementdevice and said first and second grippers, and said sausage displacementdevice and said first and second grippers being arranged on said guidesupport surfaces for opposite relative longitudinal direction movementalong said guide support surfaces such that during displacement of thesausage by said sausage displacement device in a first longitudinaldirection said first and second grippers move in an opposite, secondlongitudinal direction while skin is removed from the sausage.
 18. Theapparatus of claim 17 wherein said first side and second side skingripper assemblies each comprise a pair of plates and means for movingsaid plates into a clamping relationship relative to the skin.
 19. Theapparatus of claim 17 wherein said gripper adjustment device includes anobliquely oriented movement track relative to the longitudinal directionfor providing both transverse component and longitudinal componentmovement is said first and second grippers.
 20. The apparatus of claim17 further comprising an abutment member which limits a degree ofmovement of the sausage in the transverse direction during grippersadjustment by said gripper adjustment mechanism away from the sausage.21. The apparatus of claim 17 wherein said knife is disposed to form alongitudinal incision over at least a portion of the skin of the sausageduring displacement of the sausage by said displacement device.
 22. Theapparatus of claim 21 wherein said displacement device is positioned forcontact with a first end of the sausage, and said knife and first andsecond grippers are positioned for initial contact at an opposite end ofthe sausage.
 23. An apparatus for removing the skin (7) from a sausage(1) comprising a substrate for support, gripping means (3), a knife (6)and a displacement device (8), characterized in that said gripping means(3) are disposed for contact on opposing sides of the sausage (1), andthat the knife (6) is disposed at a surface of the sausage (1) betweensaid gripping means, wherein said gripping means are disposed for skinpinching contact on diametrically opposing sides of the sausage.
 24. Theapparatus as recited in claim 23 wherein said knife is positioned at anintermediate location between said diametrically opposed sides of thesausage.